Compressor



Oct. 24, 1950 ALDlNGER 2,526,922

COMPRESSOR Filed June 11, 1946 3 Sheets-Sheet l Fial I N VEN TOR. J acob G.A1din9er D2 68. Bg William W. Aldinger Oct- 24, 1950 J. ca. ALDINGER 2,526,922

COMPRESSOR 3 Sheets-Sheet 3 INVENTOR. Jacob G.A1dinger Doc'd.

Bg WilliamWA'ldinger xcuor Aiiornegze Patented Oct. 24, 1950 Pa., by William W. Aldinger, executor, Springfield, Pa., assignor to YorkfCorporation, a corporation of Delaware Application June 11, 1946, Serial No. 676,027 a r This invention relates to compressors, and particularly to an unloading device therefor.

The invention is primarily intended for use in refrigeration compressors and will be described as so embodied, but without implying limitation of the invention to this field.

Refrigeration compressors commonly are of the trunk piston type, single acting with the inlet valve in the piston and the discharge valvein the head. The suction or intake connection commonly leads to the crank case or to a port which leads through the cylinder wall to and through the side of the piston. Both constructions are known and the invention can be used with either.

To secure freely acting valves and large port areas the inlet valves in the piston and the discharge valve in the head are desirably of the light weight ring variety.

According to the invention the unloading valve also is of the ring type, and works in an annular groove which encircles the cylinder at the junction of the cylinder walls with the cylinder head. This arrangement ofiers many advantages. The unloading valve seat has ports which are almost continuous and encircle the cylinder. Adequate port area may be had without difiiculty because no severe limits are imposed on port width. The unloading passages from the ports to the intake are short. The valve can be forced from its seat by rotating a ring which encircles the cylinder. Means for rotating such rings are readily adaptable to various cylinder arrangements common in multi-cylinder compressors.

In'this way a simple compact arrangement giving a large area with a short unloading path is had with no change in the inlet valve, and no impairment of its size, arrangement or action. In fact the inlet valve continues to function while the compressor is unloaded, so that gas is circulated and the cylinder is cooled.

The invention will now be described by reference to the accompanying drawings in which: Fig. 1 is an axial section through one cylinder of a compressor embodying the invention, the plane of section being parallel to the axis of the crank shaft. The unloading valve is shown open. The compressor is one designed for use with one of the halogenated hydrocarbonrefrigerants, in this example dichlorodifluoromethane. K

Fig. 2 is a section on the line 2-2 of Fig. 1. Fig. 3 is a fragmentary view similar to a portion of Fig. 1, showing the unloading valve closed. Fig. 4 is a perspective view of the unloading valve and its actuating ring. 1

5 Claims. (Cl. 23024) Fig. 5 is an indicator card taken on the illustrated compressor I T Fig. 6 is an indicator card from a similar-compressor designed for ammonia.

Referring to Figs. 1-3, and particularly Fig. 1. The main housing is generally indicated by the numeral II and the cap by l2.

A cylinder liner [3 is removably mounted in housing II and is positioned by flange M which fits against a shoulder in a seat formed for it in housing II. The liner has inlet ports l5 which lead from the compressor inlet chamber 16'.

The cylinder head proper is shown at I! and is held to housing II by studs or bolts, one of which appears at IS. The head seats in a gasket l9 and holds the liner in place in the housing I l. Thus the passage 2! above head ll and within cap I2 is the discharge passage of the compressor.

As will readily be understood, Fig. 1 shows merely the end cylinder of a r'ow'of two or more, arranged "in line, so that chamber I6 is the inlet passage for all these cylinders and chamber seats 24, 25 are continuous and the ports are continuous except for the necessary bridges. The valves 26 are guided, and are limited as tov lift by a guard spider 21 held to head I! by a center bolt 28 and machine screws 29.

The head I! has an annular groove 3I'concentric with the cylinder liner and oppositefiange M from which that portion of the head I! is spaced, as shown. Guided in groove 3! is a ring valve 32, which is the unloader valve: and controls unloading ports 33 leading through flange 14 from the Working space within liner l3 to the inlet chamber IS. The middle annular area of the lower face of valve 32 is relieved or recessed as shown to provide two sealing rims which engage the upper face of flange M on opposite sides of ports 33.

Valve 32 is biased in a closing direction (downward) by three coil compression springs 34 housed in pockets formed in the valve. Any. desired number of springs could be used. The valve is shown open in Fig. 1 and closed in Fig. 3. The valve may be forced open against the urge of the springs by three pins 35 which are longitudinally reciprocablein guide ways; ,drilled in the flanged upper portion 01' liner l3. Three pins are suflicient but more can be used. The pins are actuated in unison by inclined cams 38 on a ring 31 swiveled on the liner I3 between shoulders 38, 39.

The ring 31 is constructed with a gap 4| (see Fig. 4), so that it may be sprung to pass it over the lower shoulder 39. Once in place a bridge piece 42 is fixed in place with socket-headed screws, closing only part of the gap 4|. The remainder of gap 4| receives a spherical lug 43 mounted on actuating plunger 44.

Plunger 44 obviously may actuate in unison the rings 31 of a plurality of alined cylinders, but the invention is not concerned with that detail.

Plunger 44 is biased in unloading direction (to the right in Figs. 1 and 2) by a coil compression spring 45. It may be forced to the left by a piston 46 in cylinder 41 when pressure fluid is admitted to the cylinder through connection 48. Any ,preferred pressure fluid may be led to connection 48 and may be controlled in any preferred way. In one commercial embodiment the pressure lubricating system of the compressor is connected to connection 48; sothat the compressor unloads automatically as it stops, and will not be again loaded unless-it has run long enough to develop an efiective lubricating pressure. This is a; known expedient in the art, but any control scheme may be used so as to adapt the unloading function to the needs ofparticular cases.

The piston and the inlet valve carried thereby are conventional and hence require only brie description. 1

The piston is of the hour glass type with a" piston pin 52 and two rings 53' above the pin and two below. Of the latter 54 is a ventilated oil ring and 55 is an oil scraping ring. positions of the piston the inlet ports l5 are below rings 53 and above ring 54.

As will be readily understood the parts 55 are struts, so that the spaces 56 communicate freely with space ST-beneath the piston head. The con- I These valve rings are guided and confinedby a guard ring 64, held to the inserts by machine screws, one of which appears at B5.

The guard ring 64 is designed-to fill the recess 5 -22 and the lower portion of the ports 23, so that clearance-volume is reduced to the practicable minimum.

It should be observed that ports 33 are interrupted only to the extent ne'cessaiy to afford guides for pins 35. Hence, the ports are of large area. As shown in Figs. 1 and 3, they can be, and are, notably short.

When the unloading valve is open the working space is in free communication with the inlet chamber l6 and the inlet valves 63 are free to act. Thus, gas surges as the piston reciprocates,

but there is also some circulation, which brings the gas in chamber I 6 into the circulatory flow and gives a better cooling effect.

Fig. 5 shows cards for the illustrated compressor operating on dichlorodifluoromethane. "The cards are drawn superposed at the same scale. The full line A shows a cylinder operating "fully loaded. The dot and dash line B shows modifying factors were identical.

In all the card for a cylinder unloaded by opening the valve 32. It should be understood that this card was taken on a multi-cylinder compressor and that all other cylinders of the compressor except the one in question were fully loaded. The area of the card is remarkably small. The dotted line C' shows the same cylinder unloaded by blocking the inlet valve 63 wide open while operating with the valve 32 closed. As was the case with card B, all other cylinders of the multi-cylinder compressor were operatin fully loaded. As to all three cards, the conditions as to speed and other Observe that the area for card C is much larger than the area for card B and since the area of this unloaded card represents wasted work, the fact demonstrates the superiority of applicants unloading valve.

Similar tests were made with ammonia, to make .sure that the results were attainable regardless of the refrigerant used. The compressor was similarly constructed, but was water-cooled and the lifts of the valves were designed for ammonia. Fig. 6, in which A, B and 'C' conform to A, B and C in Fig. 5, shows that the advantage is smaller. in the absolute sense with ammonia, but still appreciable, .for card is smaller than C.

What is claimed is:

l. Ina compressor, the combination ofv a reciprocable piston; means forming-a cylinder and a head therefor, the piston being reciprocable in the cylinder toward and from the head andserV- ing with said cylinder and head to enclose a working space, said cylinder and head being so formed as toaffordat substantially their junction, and extending beyond the limit of piston travel, an annular space which encircles and communicates with said working spacersaid annular space being defined by at least two opposed walls one of whichserves as a valve seat and is provided with an annular series of unloading ports and the opposite one of which. is formed with an annular guide groove for guiding and shrouding an annular unloading valve in motion toward and from said valve seat; an unloading valve guided and always at least partially shrouded by said groove and adapted to close against said seat; means operable to open and close said unloading valve; and inlet and discharge valves for said working space.

2. The combination defined in claim 1 in which the inlet valve is of the ring type and controls ports in the piston and the discharge valve 'is of the ring type and controls ports in the :head, and

the lift of the unloading valve is greater than here.

4. The combination defined in claim 1 in which the cylinder head is removable from thecylinder. the annular valve-shrouding groove is formed in the head and the annular space is defined at least inpart by the head.

5. The combination defined in claim 1 in which the cylinder head is removable from the cylinder,

the annular valve-shrouding groove is formed in UNITED STATES PATENTS the head, the annular space is defined at least N m N in part by the head, and the unloading-valve 22 i' g fi seat and its ports are formed on a portion of the 1f678'905 Goldberg July 1928 cylinder- 5 2"074911 Hull 7 "Z l Mar 23 1937 f ALDINGER' 2,140,328 Mozier Dec. 13, 1938 Executor o the Last W111 and Testament of 2164 405 Hintze July 4 1939 Jacob Aldmgerneceasei 2:185:473 Neeson 11:11:: Jan. 2, 1940 REFERENCES CITED 10 3 1 19! Ja 1944 The following references are of record in the file of this patent: 

